1Department of Urology, Ankara Ataturk Training and Research Hospital, Ankara 06800, Turkey.
2Department of Anesthesia and Reanimation, Ankara Yüksekİhtisas Training and Research Hospital, University of Medical Sciences, Ankara 06230, Turkey.
© The Author(s) 2018. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing, adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Technology keeps advancing in this era allowing surgery to become less invasive in many surgical sciences. Besides these technological advances, minimally invasive procedures such as laparoscopy and robotic assisted laparoscopy are preferred widely around the globe by both surgeons and patients. Because of the increasing demand to laparoscopy and robotic surgery, anesthetists also should adapt to these specific surgical procedures. Carbon dioxide (CO2) insufflation is applied in these procedures in order to provide working space and exposure to target organs. CO2 insufflation (pneumoperitoneum if applied intrabdominally) and positional maneuvers such as steep Trendelenburg position is used in urologic laparoscopy and robotic surgery, which have vital effects on patient’s physiology regarding cardiovascular, respiratory, renal, ocular and neurological systems. Special positions and unique surgical tools used in these procedures may hinder vital interventions such as cardiopulmonary resuscitation and open conversion. Comprehension of these pathophysiological effects and specific considerations is crucial to detect, to prevent and to manage serious complications that may occur during surgery.
Anesthesia, complications, laparoscopy, pathophysiological changes robotic surgery, urologic surgery
Minimally invasive surgery is now being applied more and more frequently in urology practice as it is in other surgical sciences. With the advances in technology, robotics had started to be used in surgery and robotic surgery followed the widespread use of laparoscopic surgery. Many oncological and reconstructive surgical operations are performed worldwide with laparoscopic and robotic assisted laparoscopic surgery. Although the aim of the procedures and the results obtained with the application of laparoscopic surgical techniques seem similar, the physiological effects of laparoscopy are very different from open surgery; therefore minimal invasive surgery certainly requires a specific anesthetic management[1,2]. For laparoscopic and robotic assisted laparoscopic operations, pneumoperitoneum is essential to provide the working area. The most common gas to provide the pneumoperitoneum is carbon dioxide (CO2). The metabolic profile created by the absorption of CO2 gas and the effect of abdominal or retroperitoneal high pressures, especially on the respiratory and circulatory system, can compromise the anesthetic management of laparoscopic procedures. This becomes even more complicated in operations where steep Trendelenburg position is combined, such as robotic radical cystectomy and robotic radical prostatectomy. Combination of pneumoperitoneum with steep Trendelenburg position in these operations may increase the risk of hemodynamic, respiratory and hemostatic disorders[3-5]. In order to provide the proper management of the patient undergone a laparoscopic or robotic assisted laparoscopic surgery and avoid the complications; one must thoroughly understand the effects of CO2 pneumoperitoneum and Trendelenburg position.
For an adequate working space and exposure to the target area of the operation, initially pneumoperitoneum is provided and usually CO2 gas is used for the procedure. Pressure levels change between 12-15 mmHg in most cases. However up to 20 mmHg pressures are reported in the literature. CO2 insufflation is applied through a Veress needle or through a trocar if open Hasson technique is used. In some procedures such as robotic radical prostatectomy or robotic radical cystectomy, applying Trendelenburg position may also be mandatory because the intestines might obscure the vision. In order to have adequate exposure; the bowels must be removed from targeted area of surgery by applying Trendelenburg position. But pneumoperitoneum (both by increasing the intra-abdominal pressure and by causing hypercarbia) and Trendelenburg position itself has considerable effects on cardiac, pulmonary, renal and cerebrovascular physiology[5-7].
With the beginning of insufflation CO2 gas starts to fill the cavity where the operation will be carried on. It is highly diffusible in the body and highly soluble in blood. CO2 exposure may lead to hypercarbia. Hypercarbia increases with higher pressures and longer exposure times. The respiratory system is the major way to excrete the CO2. Pneumoperitoneum with high intrabdominal pressures and Trendelenburg position may affect the excretion of CO2. Therefore, higher CO2 pressure both increases the absorption and decreases the exhaustion. The dissolved CO2 in blood increases H+ ions and causes acidosis. Hypercarbia and acidosis decrease the cardiac contractility, make myocardium more sensitive to catecholamines and cause peripheral vasodilatation. But with the sympathetic activation caused by hypercarbia it finally leads to tachycardia and vasoconstriction. During laparoscopic or robotic operations in urology both transperitoneal (TP) and extraperitoneal (EP) techniques are used. Although both approaches seem to have similar consequences there are minor differences observed during CO2 insufflation. In their research comparing the effects of CO2 insufflation on hemodynamics, oxygen levels and acid-base homeostasis in TP vs. EP robot-assisted laparosopic radical prostatectomy (RALRP), Dal Moro et al. reported that, EP approach causes a higher absorption of CO2, thus a more rapid acidosis. Although in both approaches there were similar operative times and there was even a less extreme Trendelenburg position in EP approach, EP RALRP was more relevant with CO2 absorption and acidosis. A similar study by Meininger et al. also reports that CO2 absorption was more pronounced with EP approach than TP. However the reasons for these consequences seem to be multifactorial and have not been yet clarified.
TP approach is frequently preferred in urological surgery as it provides a familiar anatomic perspective to the surgeon and it is thought to be an easier technique to master at. However, EP approach may also be preferred, and both techniques have advantages and disadvantages. CO2 insufflation to abdominal cavity creates pneumoperitoneum. CO2 insufflation makes considerable pathophysiological affects by causing hypercarbia and acidosis. Apart from that pneumoperitoneum increases intra-abdominal pressure (IAP) which may cause serious cardiovascular, respiratory and neurological effects[5-7,11-13]. Trendelenburg position also effects negatively by decreasing pulmonary compliance and functional residual capacity[14-16].
The effects of pneumoperitoneum on hemodynamics is highly depended on the level of IAP, and patient position. With the initiation of pneumoperitoneum mean arterial pressure (MAP) and systemic vascular resistance (SVR) increase > 25% and 20% respectively, however SVR returns to basal after providing Trendelenburg position. Increased IAP decreases the venous return and cardiac output but Trendelenburg position reversely increases the venous return and it may neutralize this effect. But of course these effects alter with the level of IAP. IAP lower than 15 mmHg causes increase in cardiac output by applying pressure to splanchnic venous bed and sympathetic stimulation caused by hypercarbia contributes by providing peripheral vasoconstriction and increasing cardiac motility. On the other hand IAP > 15 mmHg applies compression over inferior vena cava and preload decreases causing hypotension. Another significant factor in laparoscopy that has effect on hemodynamics is vagal stimulation. Vagal stimulation may be initiated by peritoneal expansion caused by pneumoperitoneum, by direct stimulation of peritoneum with Veress needle or trocars or as a result of gas embolism (CO2 embolism). Vagal stimulation may cause bradyarrhythmia (in a range from bradycardia to asystole) and hypotension[7,20]. Tachyarrhythmia may also be experienced as a result of sympathetic activation caused by hypercarbia. The effects of pneumoperitoneum and Trendelenburg position on hemodynamics are usually well tolerated in patients with normal cardiac function, but it has been reported that even in elderly patients with ASA 2-3 risk or even in patients with underlying heart conditions such as aortic stenosis, laparoscopic operations may still be safely performed with adequate monitoring and being aware of possible complications[21,22]. High insufflation pressures and hypercarbia caused by long operative times or CO2 venous embolism increases the risk of cardiovascular complications.
During laparoscopy insufflation increases IAP which causes an increase in peak airway pressures and a decrease in lung volumes and pulmonary compliance. Particularly in operations such as RALRP or robotic cystectomy cephalad shift of diaphragm related to high IAP gets more severe by the addition of Trendelenburg position, because the abdominal contents push the diaphragm. Eventually atelectasis may occur and functional residual capacity may decrease and a ventilation-perfusion mismatch may develop. These changes may lead to hypercarbia and hypoxemia. Moreover, high IAP increases the risk of barotrauma which may lead to pneumothorax or pneumomediastinum. These effects on respiratory system do not immediately return to normal postoperatively. Studies show that regaining full function of lungs may take 5 days postoperatively in patients without pulmonary disease, while it may take more than 5 days in patients with chronic obstructive pulmonary disease (COPD). Therefore patients with COPD should be advised to continue pulmonary rehabilitation even after being discharged.
Pneumoperitoneum and Trendelenburg position are both found to increase the intracranial pressure (ICP)[5,13,24,25]. During pneumoperitoneum increased IAP prevents the venous return from lumbar venous plexus thus causing ICP to increase. Cerebral venous drainage is hindered and cerebral intravascular volume is increased. Due to these reasons ICP increases. Also combining pneumoperitoneum with Trendelenburg increases the ICP further and this may hinder cerebral oxygenation. Kalmar et al. examined patients undergoing RALRP which were exposed to prolonged steep Trendelenburg position and CO2 pneumoperitoneum and suggested that it does not compromise cerebral perfusion. Though, it is advised to keep the patient in normocapnic range because regional cerebral oxygen saturation (rSO2) is correlated with the increase in partial pressure of CO2 (PaCO2). If the patient has already an increased ICP caused by various reasons or there is a risk of cerebral ischemia inducing with pneumoperitoneum and applying Trendelenburg position may cause no toleration due to ICP increase and severe cerebrovascular complications.
Pathophysiological changes during laparoscopy and robotic surgery has been already discussed. Most of these effects are well tolerated if a proper anesthetic care is provided in healthy patients. But even in healthy patients undesired consequences may be experienced. In order to prevent serious morbidity and mortality management of complications should be taken seriously and a coordinated crisis plan should be ready to be executed. Patients should be properly monitored to understand the current situation, to maintain stability and to avoid the complications with the necessary interventions on time. Standard monitoring includes electrocardiogram, non-invasive blood pressure, pulse oximetry, end tidal CO2 concentration and urine output. Also in major surgery, hemodynamically unstable patients or in patients with cardiovascular disease intra-arterial blood pressure may be monitored by arterial cannulation[21,28].
Cardiovascular complications related to laparoscopy begin to emerge with CO2 insufflation. Hypotension, hypertension, arrhythmias and cardiac arrest may be encountered during laparoscopy. As the Trendelenburg position has the risk of increasing the risk of these complications, it may be wise to create the pneumoperitoneum in horizontal position rather than down-tilted. CO2 insufflation and positional changes should be applied gradually as sudden changes may affect hemodynamic stability. Monitoring IAP is also mandatory, because it is one of the main reasons of changes on hemodynamics. Keeping the IAP low may allow avoiding many complications related to carboperitoneum. IAP > 15 mmHg increases cardiovascular risk as inferior vena cava is compressed and eventually preload decreases. Additionally atropine might be administrated before the initiation of pneumoperitoneum or it may be kept ready for administration to prevent the brady-arrhythmias related to vagal reflex. Acid-base homeostasis is instable in laparoscopic surgery because of the CO2 insufflated and the decrease in pulmonary compliance. It is essential to monitor pH levels and PaCO2 in order to keep the patient in normocapnic range and in ideal pH level, as it effects the cardiovascular efficiency and stability. If the patient has a cardiovascular disease the anesthetist should avoid using cardio-depressant drugs. If there is an increase in MAP due to increase in SVR, instead of increasing the concentration of inhalation anesthetics (which may cause myocardial depression, especially in patients with cardiovascular disease) administrating vasodilating agents reducing specifically preload or afterload should be considered[21,28]. However studies report that even in cases which pneumoperitoneum is combined with steep Trendelenburg position (such as RALRP) a deterioration of cardiac function was not present and patients usually tolerate the changes well[3,29]. However, the position and pneumoperitoneum may aggravate mitral deficiency, so it must be kept in mind if a mitral deficiency exists. If a cardiovascular complication is thought to be aggravated or caused by the position or pneumoperitoneum, first IAP should be decreased and if it does not work, CO2 insufflation should be ceased, gas should be evacuated and position should be reversed to horizontal state. Venous gas embolism is a complication possible to occur during laparoscopic or robotic surgery that may have fatal consequences. It may occur during CO2 insufflation or during surgical procedure especially if venous structures are involved. During insufflation if the Veress needle is inserted directly into vascular structures results may be much more catastrophic. If the structural integrity of a major vein is disrupted, the risk of gas embolism increases. But it does not have to be a major vein. During transection the dorsal venous complex in RALRP operations subclinical CO2 gas embolism can be observed as reported in literature[30,31]. The symptoms vary in a wide range; while most of gas embolisms are subclinical and can not be detected by standard monitoring, some might cause catastrophic consequences such as cardiovascular collapse[11,23,30,31]. As it is a life-threatening matter, the anesthetist should be vigilant. In the presence of a gas embolism insufflation should be ceased and the gas should be evacuated immediately. Left lateral decubitus position must be applied to prevent the gas from entering pulmonary artery. A central venous catheter should be placed for aspirating the gas and 100% O2 hyperventilation and proper cardiopulmonary resuscitation should be applied.
Possible pulmonary complications related to laparoscopy are hypoxemia, hypercarbia, barotrauma, pneumomediastinum, pneumothorax, atelectasis and pulmonary edema[7,12,32]. As it is previously mentioned increased IAP in pneumoperitoneum causes an increase in peak airway pressures, a decrease in lung volumes and a decrease in pulmonary compliance. Trendelenburg position increases these effects further. These changes cause a ventilation/perfusion (V/P) mismatch and atelectasis. Eventually hypoxemia and hypercarbia may occur due to ineffective gas exchange. Hypercarbia and respiratory acidosis may be avoided by hyperventilation, which means 15%-25% increase in minute ventilation should be maintained[12,33]. But during hyperventilation it is suggested to increase the respiratory rate and not the tidal volume; especially in patients with COPD, in patients with history of spontaneous pneumothorax or bullous emphysema; because high peak airway pressures and reduced pulmonary compliance may increase the risk of barotrauma and a spontaneous pneumothorax[33,34]. Increase in minute ventilation may be provided by using both pressure-controlled ventilation and volume-controlled ventilation. Pressure-controlled ventilation was reported to decrease peak airway pressure and increase dynamic compliance and found superior to volume controlled ventilation by Assad et al.. But Balick-Weber et al. and Choi et al. reported that these two ventilation techniques are not superior to each other regarding respiratory mechanics and hemodynamics. Endo-tracheal intubation with either volume or pressure controlled ventilation is the recommended technique, especially for longer operations, because it provides a better control over CO2 and prevents gastric regurgitation. But for shorter operations which can be performed at lower IAP levels, using conventional laryngeal mask airway (LMA) or a ProSeal® LMA (ProSeal LMA, San Diego, CA, USA) was found to be safe and effective in some laparoscopic gynecological operations and laparoscopic cholecystectomies; therefore it may be valid for laparoscopic urological operations without Trendelenburg position lasting < 2 h and performed at lower IAP levels[38-40]. Increased IAP during CO2 insufflation and Trendelenburg position may cause the distance between carina and endotracheal tube tip to become shorter leading to inadvertent endobronchial intubation and hypoxemia (due to ineffective ventilation). Endotracheal tube’s position should be checked regularly through the surgery and it should be checked if both sides are equally ventilated in order to avoid this complication. Patients without pulmonary disease usually tolerate side effects of pneumoperitoneum and Trendelenburg position well with proper anesthetic management and postoperative care. However, it may be more severe in patients with pulmonary dysfunction; so these patients must be carefully assessed preoperatively with pulmonary function tests and arterial blood gas analysis should be performed at preoperative evaluation and regularly during surgery through an artery cannula. If hypoxemia and hypercarbia persist even after proper interventions, pneumoperitoneum should be ceased and a slow re-insufflation should be applied or convertion to open surgery should be considered if necessary.
Subcutaneous emphysema is the presence of gas in subcutaneous tissue passing through a disruption in peritoneum or through an inadvertent placed trocar. In a study conducted by McAllister et al. showed, up to 56 % of the patients after laparoscopic surgery had subcutaneous emphysema. However, this situation is mostly benign and is not serious. The clinical detection rate is between 0.3%-3% in laparoscopic surgeries. Subcutaneous emphysema may extend to mediastinum and pleura causing pneumothorax and pneumomediastinum, or vice versa it may be the sign of an extended pneumothorax or pneumomediastinum to subcutaneous tissue. Most of the cases with subcutaneous emphysema is clinically insignificant, however its relevance with pneumothorax and pneumomediastinum must be remembered. Also, if the neck is involved, obstruction of upper airways may be present. Risk factor for subcutaneous emphysema are multiple trocars, end tidal CO2 levels higher than 50 mmHg, prolonged operative time and old patients. CO2 gas reserved by subcutaneous emphysema may cause hypercarbia, so increased ventilation might be necessary to cope with the increased end tidal CO2 concentrations.
There are multiple ways for a pneumothorax to occur during laparoscopic surgery. Either a real pneumothorax may occur due to high airway peak pressures causing a congenital bulla to rupture or insufflated CO2 may infiltrate thoracic cavity. Insufflated CO2 may create a capno-thorax or capno-mediastinum (pneumothorax or pneumomediastinum caused by pure CO2 that has been insufflated) through congenital or acquired (injuries caused by surgery) diaphragmatic defects, as a result of CO2 dissecting through retroperitoneum or by the extension of subcutaneous emphysema up to pleura or mediastinum. Mostly the cases are asymptomatic and conservative treatment and close observation is sufficient. However increase in peak airway pressures, hypoxemia, hypotension and even cardiac arrest may be present according to the severity of this complication[7,32]. If cardiopulmonary functions are compromised, releasing of pneumoperitoneum and placing a chest tube must be considered. Usually a chest tube insertion is sufficient. However thoracic complications after laparoscopic urologic procedures are rare and most of the cases are subclinical, thus a routine postoperative chest radiography was not found to be necessary[44,45].
Due to high IAP in laparoscopic surgeries renal perfusion and glomerular filtration rate decreases thus causing oliguria. In multiple studies on animals and humans effects of pneumoperitoneum on renal physiology were examined and the reasons, which were found responsible for this complication, are IAP applying direct compression on renal vascular structures, activation of renin-angiotensin-aldosterone, increase of anti-diuretic hormone and low cardiac output[47-49]. To prevent oliguria sufficient hydration of the patient before and during the operation must be provided and urine output must be observed especially in prolonged and major surgeries. Also using low-dose dopamine at 2 mcg/kg/min and nicardipine at 0.5 mcg/kg/min was found useful to protect kidneys from hypoperfusion and renal dysfunction[50,51].
As previously discussed neurologic complications may occur due to laparoscopic and robotic surgeries as a reason of increase in ICP, cerebral hypoperfusion or hypoxemia. High risk patients with a previous cerebrovascular disorder should be carefully assessed preoperatively. Near infrared spectroscopy may be used to monitor cerebral oxygen levels. Pneumoperitoneum and Trendelenburg position both increases ICP[13,24,25]. High ICP may cause transient or permanent neurologic deficits such as motor paralysis or paresis. In two case reports transient neurologic deficits including quadriplegia and hemiparesis were reported and both patients had full recovery[52,53].
Trendelenburg position increases intra-ocular pressure. This may cause temporary or permanent loss in vision. Ischemic optic neuropathy, which is a rare complication, was reported after robotic and laparoscopic radical prostatectomy. Corneal abrasions may occur because of chemosis or exposure keratopathy. Eye patchings and transparent occlusive dressings are recommended to prevent corneal abrasions. Prolonged operations in Trendelenburg position may cause facial, periorbital, conjunctival, pharyngeal and laryngeal edema. Edema of the upper airways might cause serious consequences after extubation. If facial edema or conjunctival edema is observed, there is a chance that laryngeal edema might also exist. Therefore if there is a suspicion of upper airway edema, an endotracheal leak test should be done before extubation.
Patient positioning is an important preparation for the operation. Improper positioning may cause nerve injuries and compartment syndrome, furthermore it may compromise cardiopulmonary function. Mills et al. investigated positioning injuries associated with robotic surgery in their institution and found that 6.6% of 334 patients had positioning injuries. These injuries resolved at least within 1 month but some persisted beyond 6 months. As well as positional effects caused by prolonged lithotomy and Trendelenburg, use of pneumatic compression stockings, intravenous fluid restriction for improvement of surgical view, hypotension and administration of vasoactive medication compromises the proper perfusion of lower extremity, thus increases the risk of compartment syndrome, especially in the lower extremities[57,58]. Compartment syndrome of the upper extremities is relatively rare in the literature, however it is possible especially if higher amounts of intravenous fluid replacement is present. Galyon et al. reported a patient with compartment syndrome in three limbs including both lower extremities and left upper extremity after a robotic cystoprostatectomy which lasted about 6 h, and for treatment fasciotomy was performed to all affected extremities. In order to avoid this serious complication pressure points of the patient must be carefully assessed and materials absorbing the pressure must be placed between the body and operating table. Also repositioning of the extremities every 2 h was found to be beneficial avoiding compartment syndrome.
Due to the positions applied to patients and surgical equipment limiting the access to patients, critical interventions such as cardiopulmonary resuscitation or conversion to open surgery may delay. This may lead to lethal consequences. Life threatening emergencies like cardiopulmonary arrest require immediate attention and intervention. Especially in robotic surgery this may be a critical issue, as before the anesthesiology team could start a resuscitation, robot must be undocked. Simulating this situation and having an emergency plan can improve the time of preparation and intervention. O’Sullivan et al. experienced a respiratory complication during a robotic sacrocolpopexy. The patient had a decreased sPO2 and increased airway pressure, thus an emergency undocking of the robotic arms was required. After this complication they reported that they created an emergency undocking protocol, which indicates the roles of each member of the crew in emergency situations. Also Huser et al. reported that proper training with repeating simulations improved the time for resuscitation in simulations. To be able to react to a life-threatening emergency swiftly, having a similar training and an emergency protocol may be useful.
Minimal invasive surgery is being increasingly more popular. The application of laparoscopic and robotic surgery is now more common. In urology, laparoscopy and robotic surgery may be applied in various operations including uro-oncological surgery. Minimally invasive surgery provides patients many benefits, however robotic and laparosopic surgery also has a risk of many significant and unique complications related to these procedures. Pneumoperitoneum and specific patient positions such as steep Trendelenburg position have important physiological effects on cardiovascular, pulmonary, ocular, renal and neurological systems which may cause serious complications. In order to detect, manage or prevent these complications properly these physiological effects must be thoroughly comprehended. All personnel in the operating theatre should be prepared to all possible complications related to surgical procedure and anesthesia. With proper interventions, careful monitoring and preventive precautions, these complications may be avoided or at least their impact may be minimized.
Conception or design of the work: Özgök A, Arslan ME
Data collection: Arslan ME
Data analysis and interpretation: Özgök A, Arslan ME
Drafting the article: Arslan ME
Critical revision of the article: Özgök A
Final approval of the version to be published: Özgök A, Arslan MEFinancial support and sponsorship
None.Conflicts of interest
There are no conflicts of interest.Patient consent
Not applicable.Ethics approval
© The Author(s) 2018.
1. Cockcroft JO, Berry CB, McGrath JS, Daugherty MO. Anesthesia for major urological surgery. Anesthesiol Clin 2015;33:165-72.DOIPubMed
2. Arunkumar R, Rebello E, Owusu-Agyemang P. Anaesthetic techniques for unique cancer surgery procedures. Best Pract Res Clin Anaesthesiol 2013;27:513-26.DOIPubMed
3. Falabella A, Moore-Jeffries E, Sullivan MJ, Nelson R, Lew M. Cardiac function during steep Trendelenburg position and CO2 pneumoperitoneum for robotic-assisted prostatectomy: a trans-oesophageal Doppler probe study. Int J Med Robot 2007;3:312-5.DOIPubMed
4. Modi PK, Kwon YS, Patel N, Dinizo M, Farber N, Zhao PT, Salmasi A, Parihar J, Ginsberg S, Ha YS, Kim IY. Safety of robot-assisted radical prostatectomy with pneumoperitoneum of 20 mmHg: a study of 751 patients. J Endourol 2015;29:1148-51.DOIPubMed
5. Kalmar AF, Foubert JF, Hendrickx JFA, Mottrie A, Absalom A, Mortier EP, Struys MM. Influence of steep Trendelenburg position and CO2 pneumoperitoneum on cardiovascular, cerebrovascular, and respiratory homeostasis during robotic prostatectomy. Br J Anaesth 2010;104:433-9.DOIPubMed
6. Awad H, Walker CM, Shaikh M, Dimitrova GT, Abaza R, O'Hara J. Anesthetic considerations for robotic prostatectomy: a review of the literature. J Clin Anesth 2012;24:494-504.DOIPubMed
7. Gutt CN, Oniu T, Mehrabi A, Schemmer P, Kashfi A, Kraus T, Büchler MW. Circulatory and respiratory complications of carbon dioxide insufflation. Dig Surg 2004;21:95-105.
8. Chen Y, Xie Y, Xue Y, Wang B, Jin X. Effects of ultrasound-guided stellate ganglion block on autonomic nervous function during CO2-pneumoperitoneum: a randomized double-blind control trial. J Clin Anesth 2016;32:255-61.DOIPubMed
9. Dal Moro F, Crestani A, Valotto C, Guttilla A, Soncin R, Mangano A, Zattoni F. Anesthesiologic effects of transperitoneal versus extraperitoneal approach during robot-assisted radical prostatectomy: results of a prospective randomized study. Int Braz J Urol 2015;41:466-72.DOIPubMedPMC
10. Meininger D, Byhahn C, Wolfram M, Mierdl S, Kessler P, Westphal K. Prolonged intraperitoneal versus extraperitoneal insufflation of carbon dioxide in patients undergoing totally endoscopic robot-assisted radical prostatectomy. Surg Endosc 2004;18:829-33.DOIPubMed
11. Gainsburg DM. Anesthetic concerns for robotic-assisted laparoscopic radical prostatectomy. Minerva Anestesiol 2012;78:596-604.
12. Gerges FJ, Kanazi GE, Jabbour-Khoury SI. Anesthesia for laparoscopy: a review. J Clin Anesth 2006;18:67-78.DOIPubMed
13. O'Malley C, Cunningham AJ. Physiologic changes during laparoscopy. Anesthesiol Clin North Am 2001;1:1-18.DOI
14. Khetarpal R, Bali K, Chatrath V, Bansal D. Anesthetic considerations in the patients of chronic obstructive pulmonary disease undergoing laparoscopic surgeries. Anesth Essays Res 2016;10:7-12.DOIPubMedPMC
15. Lian M, Zhao X, Wang H, Chen L, Li S. Respiratory dynamics and dead space to tidal volume ratio of volume-controlled versus pressure-controlled ventilation during prolonged gynecological laparoscopic surgery. Surg Endosc 2017;31:3605-13.DOIPubMed
16. Kilic OF, Börgers A, Köhne W, Musch M, Kröpfl D, Groeben H. Effects of steep Trendelenburg position for robotic-assisted prostatectomies on intra and extrathoracic airways in patients with or without chronic obstructive pulmonary disease. Br J Anaesth 2015;114:70-6.DOIPubMed
17. Lestar M, Gunnarsson L, Lagerstrand L, Wiklund P, Odeberg-Wernerman S. Hemodynamic perturbations during robot-assisted laparoscopic radical prostatectomy in 45° Trendelenburg position. Anesth Analg 2011;113:1069-75.DOIPubMed
18. Odeberg S, Ljungqvist O, Sevenberg T, Gannedahl P, Bäckdahl M, von Rosen A, Sollevi A. Haemodynamic effects of pneumoperitoneum and the influence of posture during anaesthesia for laparoscopic surgery. Acta Anaesthesiol Scand 1994;38:276-83.DOIPubMed
19. Irwin MG, Wong SSC. Anaesthesia and minimally invasive surgery. Anaesth Intensive Care Med 2015;16:17-20.DOI
20. Yong J, Hibbert P, Runciman WB, Coventry BJ. Bradycardia as an early warning sign for cardiac arrest during routine laparoscopic surgery. Int J Qual Health Care 2015;27:473-8.DOIPubMed
21. Rosendal C, Markin S, Hien MD, Motsch J, Roggenbach J. Cardiac and hemodynamic consequences during capnoperitoneum and steep Trendelenburg positioning: lessons learned from robot-assisted laparoscopic prostatectomy. J Clin Anesth 2014;26:383-9.DOIPubMed
22. Sonny A, Sessler DI, You J, Kashy BK, Sarwar S, Singh AK, Sale S, Alfirevic A, Duncan AE. The response to Trendelenburg position is minimally affected by underlying hemodynamic conditions in patients with aortic stenosis. J Anesth 2017;31:692-702.DOIPubMed
23. Baltayian S. A brief review: anesthesia for robotic surgery. J Robotic Surg 2008;2:59-66.DOIPubMed
24. Robba C, Cardim D, Donnelly J, Bertuccio A, Bacigaluppi S, Bragazzi N, Cabella B, Liu X, Matta B, Lattuada M, Czosnyka M. Effects of pneumoperitoneum and Trendelenburg position on intracranial pressure assessed using different non-invasive methods. Br J Anaesth 2016;117:783-91.DOIPubMed
25. Kim MS, Bai SJ, Lee JR, Choi YD, Kim YJ, Choi SH. Increase in intracranial pressure during carbon dioxide pneumoperitoneum with steep Trendelenburg positioning proven by ultrasonographic measurement of optic nerve sheath diameter. J Endourol 2014;28:801-6.DOIPubMed
26. Lahaye L, Grasso M, Green J, Biddle CJ. Cerebral tissue O2 saturation during prolonged robotic surgery in the steep Trendelenburg position: an observational case series in a diverse surgical population. J Robot Surg 2015;9:19-25.DOIPubMed
27. Kalmar AF, Dewaele F, Foubert L, Hendrickx JF, Heeremans EH, Struys MM, Absalom A. Cerebral haemodynamic physiology during steep Trendelenburg position and CO2 pneumoperitoneum. Br J Anaesth 2012;108:478-84.DOIPubMed
28. Sood J. Advancing frontiers in anaesthesiology with laparoscopy. World J Gastroenterol 2014;20:14308-14.DOIPubMedPMC
29. Haas S, Haese A, Goetz AE, Kubitz JC. Haemodynamics and cardiac function during robotic-assisted laparoscopic prostatectomy in steep Trendelenburg position. Int J Med Robot 2011;7:408-13.DOIPubMed
30. Hong JY, Kim JY, Choi YD, Rha KH, Yoon SJ, Kil HK. Incidence of venous gas embolism during robotic-assisted laparoscopic radical prostatectomy is lower than that during radical retropubic prostatectomy. Br J Anaesth 2010;105:777-81.DOIPubMed
31. Hong JY, Kim WO, Kil HK. Detection of subclinical CO2 Embolism by transesophageal echocardiography during laparoscopic radical prostatectomy. Urology 2010;75:581-4.DOIPubMed
32. Joshi GP. Complications of laparoscopy. Anesthesiol Clin North America 2001;19:89-105.DOI
33. Salihoglu Z, Demiroluk S, Dikmen Y. Respiratory mechanics in morbid obese patients with chronic obstructive pulmonary disease and hypertension during pneumoperitoneum. Eur J Anaesthesiol 2003;20:658-61.DOIPubMed
34. Bauman TM, Potretzke AM, Vetter JM, Bhayani SB, Figenshau RS. Cerebrovascular disease and chronic obstructive pulmonary disease increase risk of complications with robotic partial nephrectomy. J Endourol 2016;30:293-9.DOIPubMed
35. Assad OM, El Sayed AA, Khalil MA. Comparison of volume controlled ventilation and pressure-controlled ventilation volume guaranteed during laparoscopic surgery in Trendelenburg position. J Clin Anesth 2016;34:55-61.DOIPubMed
36. Balick-Weber CC, Nicolas P, Hedreville-Montout M, Blanchet P, Stéphan F. Respiratory and haemodynamic effects of volume-controlled vs pressure-controlled ventilation during laparoscopy: a cross-over study with echocardiographic assessment. Br J Anaesth 2007;99:429-35.DOIPubMed
37. Choi EM, Na S, Choi SH, An J, Rha KH, Oh YJ. Comparison of volume-controlled and pressure-controlled ventilation in steep Trendelenburg position for robot-assisted laparoscopic radical prostatectomy. J Clin Anesth 2011;23:183-8.DOIPubMed
38. Maltby JR, Beriault MT, Watson NC, Liepert D, Fick GH. The LMA-ProSeal is an effective alternative to tracheal intubation for laparoscopic cholecystectomy. Can J Anaesth 2002;49:857-62.DOIPubMed
39. Lan S, Zhou Y, Li JT, Zhao ZZ, Liu Y. Influence of lateral position and pneumoperitoneum on oropharyngeal leak pressure with two types of laryngeal mask airways. Acta Anaesthesiol Scand 2017;61:1114-21.DOIPubMed
40. Rustagi P, Patkar GA, Ourasang AK, Tendolkar BA. Effect of pneumoperitoneum and lateral position on oropharyngeal seal pressures of ProsealLMA in laparoscopic urological procedures. J Clin Diagn Res 2017;11:UC05-9.
41. Chang CH, Lee HK, Nam SH. The displacement of the tracheal tube during robot-assisted radical prostatectomy. Eur J Anaesthesiol 2010;27:478-80.DOIPubMed
42. McAllister JD, D'Altorio RA, Snyder A. CT findings after uncomplicated percutaneous laparoscopic cholecsytectomy. J Comput Assist Tomogr 1991;15:770-2.DOIPubMed
43. Özgök A, Kazanci D. Anesthesiology in robotic surgery and robotic radical prostatectomy. Robot Lap Endosurg 2016;2:30-3.
44. Mari A, Antonelli A, Bertolo R, Bianchi G, Borghesi M, Ficarra V, Fiori C, Furlan M, Giancane S, Longo N, Mirone V, Morgia G, Porpiglia F, Rovereto B, Schiavina R, Serni S, Simeone C, Volpe A, Carini M, Minervini A. Predictive factors of overall and major postoperative complications after partial nephrectomy: results from a multicenter prospective study (The RECORd 1 project). Eur J Surg Oncol 2017;43:823-30.DOIPubMed
45. Zhao LC, Han JS, Loeb S, Tenggardjaja C, Rubenstein RA, Smith ND, Nadler RB. Thoracic complications of urologic laparoscopy: correlation between radiographic findings and clinical manifestations. J Endourol 2008;22:607-14.DOIPubMed
46. Nguyen NT, Perez RV, Fleming N, Rivers R, Wolfe BM. Effect of prolonged pneumoperitoneum on intraoperative urine output during laparoscopic gastric bypass. J Am Coll Surg 2002;195:476-83.DOI
47. Sodha S, Nazarian S, Adshead JM, Vasdev N, Mohan-S G. Effect of pneumoperitoneum on renal function and physiology in patients undergoing robotic renal surgery. Curr Urol 2016;9:1-4.DOIPubMedPMC
48. Wever KE, Bruintjes MH, Warlé MC, Hooijmans CR. Renal perfusion and function during pneumoperitoneum: a systematic review and meta-analysis of animal studies. PLoS One 2016;11:e0163419.
49. Lee JY, Choi SH. Results of hepatic and renal function tests to different CO2 pneumoperitoneum conditions: an experimental capnoperitoneum study in dogs. Res Vet Sci 2015;101:1-5.DOIPubMed
50. Russo A, Bevilacqua F, Scagliusi A, Scarano A, Di Stasio E, Marana R, Marana E. Dopamine infusion and fluid administration improve renal function during laparoscopic surgery. Minerva Anestesiol 2014;80:452-60.
51. Huh H, Kim NY, Park SJ, Cho JE. Effect of nicardipine on renal function following robot-assisted laparoscopic radical prostatectomy in patients with pre-existing renal insufficiency. J Int Med Res 2014;42:427-35.DOIPubMed
52. Deem S, Davis CR, Tierney JP. Transient paralysis after robotic prostatectomy. J Robot Surg 2008;2:45-6.DOIPubMedPMC
53. Pandey R, Garg R, Darlong V, Punj J, Chandralekha. Hemiparesis after robotic laparoscopic radical cystectomy and ileal conduit formation in steep Trendelenburg position. J Robot Surg 2012;6:269-71.DOIPubMed
54. Adisa AO, Onakpoya OH, Adenekan AT, Awe OO. Intraocular pressure changes with positioning during laparoscopy. JSLS 2016;20:e2016.00078.
55. Ozcan MF, Akbulut Z, Gurdal C, Tan S, Yildiz Y, Bayraktar S, Ozcan AN, Ener K, Altinova S, Arslan ME, Balbay MD. Does steep Trendelenburg positioning effect the ocular hemodynamics and intraocular pressure in patients undergoing robotic cystectomy and robotic prostatectomy? Int Urol Nephrol 2017;49:55-60.
56. Mills JT, Burris MB, Warburton DJ, Conaway MR, Schenkman NS, Krupski TL. Positioning injuries associated with robotic assisted urological surgery. J Urol 2013;190:580-4.DOIPubMed
57. Danic MJ, Chow M, Alexander G, Bhandari A, Menon M, Brown M. Anesthesia considerations for robotic-assisted laparoscopic prostatectomy: a review of 1,500 cases. J Robotic Surg 2007;1:119-23.DOIPubMedPMC
58. Galyon SW, Richards KA, Pettus JA, Bodin SG. Three-limb compartment syndrome and rhabdomyolysis after robotic cystoprostatectomy. J Clin Anesth 2011;23:75-8.DOIPubMed
59. Kochiashvili D, Sutidze M, Tchovelidze CH, Rukhadze I, Dzneladze A. Compartment syndrome, rhabdomyolysis and risk of acute renal failure as complications of the urological surgery. Georgian Med News 2007;(143):45-9.
60. O'Sullivan OE, O'Sullivan S, Hewitt M, O'Reilly BA. Da Vinci robot emergency undocking protocol. J Robot Surg 2016;10:251-3.DOIPubMed
61. Huser AS, Müller D, Brunkhorst V, Kannisto P, Musch M, Kröpfl D, Groeben H. Simulated life-threatening emergency during robot-assisted surgery. J Endourol 2014;28:717-21.DOIPubMed
Marco Echeverria-Villalobos et al., Vessel Plus, 2019
Francesco Colombo et al., Vessel Plus, 2019
Jan Willem van den Berg et al., Mini-invasive Surgery, 2019
Fernando A. M. Herbella et al., Mini-invasive Surgery, 2019
Lazzaro Paraggio et al., Vessel Plus, 2019
Michael Yaroustovsky et al., Vessel Plus, 2019
Ken Yuu et al., Mini-invasive Surgery, 2019
Yasushi Ohmura et al., Mini-invasive Surgery, 2019
Miriam Cortes-Cerisuelo et al., Mini-invasive Surgery, 2019
Marta Climent et al., Mini-invasive Surgery, 2018