Low-pressure and Gasless Laparascopy in Abdominal Surgery

Knowledge of pathophysiological basis of laparoscopic procedures, that is, the influence of CO2 pneumoperitoneum (PNP) on the body in particular, can prevent the complications during laparoscopy to occur. Standard intra-abdominal pressure (IAP), which is used during laparoscopic surgery, is 12-15 mm / Hg. The direct effect of CO2 pneumoperitoneum is a result of mechanical action of the gas and increasement of intra-abdominal pressure (IAP). The indirect effect of CO2 pneumoperitoneum is caused by the absorption of gas inserted into the abdomen. Analysis of published articles that assess the effects of CO2 pneumoperitoneum on the body and abdominal organs contributes to a better usage of the laparoscopic method. Different techniques in laparoscopy, created as an alternative to standard CO2-pneumoperitoneum, have the task to reduce the risks for patients with comorbidity and simultaneously raise the abdominal wall and allow the surgeon to perform smooth operation, which is especially important for ASA III and ASA IV patients. Alternative techniques can be divided into three groups: laparoscopy using pneumoperitoneum with low intra-abdominal pressure (up to 8 mm / Hg), laparoscopy using retractors abdominal wall and limited pneumoperitoneum, and laparoscopy without the use of gas (gasless laparoscopy; raising the abdominal wall retractor only ). Low insufflation pressure in the abdomen (up to 8 mm / Hg) is beneficial for patients with laparoscopic procedures and its routine usage in elderly patients and patients with severe cardiorespiratory diseases, should be common practice. Gasless laparoscopy was created because of the need to prevent the negative effects of increased intra-abdominal pressure on the body during laparoscopy, primarily in patients with high comorbidity (ASA III and ASA IV). When compared to other techniques, numerous studies prefer laparoscopy with low insufflation pressure, but in practice this is not done routinely, yet each technique is applied selectively, according to the needs and condition of the patient, which is the most appropriate. To avoid the side effects of CO2 pneumoperitoneum, which is important in high-risk patients, it is more likely to operate on low IAP (6-8 mm / Hg) or use gasless laparoscopy. This is especially important for long – duration operations. DOI: 10.7251/SMDEN1501066H (Scr Med 2015:46:66-72)


Introduction
Controlled insufflation pressure within the abdominal cavity has the task to enable the smooth operation to the surgeon, lifting the front abdominal wall up and pushing other abdominal organs and soft tissues back.CO2 gas is considered to be the most approprite for insufflation into the abdominal cavity, as it fulfills several important criteria: it is non-flammable and it is possible to use electrocauter.
Moreover, it is very soluble in blood and tissues, and may be easily ejected through the lungs, it is nontoxic and very inexpensive (Table 1. ).Other gases such as argon, helium and NO2, have been used experimentally and have not closely met the above requirements,and are therefore rarely used. 1,2. HASUKIĆ Table 1.Characteristics of an ideal gas insufflation that meets CO2 1,2 The properties of an ideal gas insufflation • colorless • antiknock • fireproof • limited feature resorption • limited physiological effects on the body after absorption • rapidly excreted from the body after absorption • does not support the occurrence of burns • limited physiological effects in the case of intravascular embolization • highly soluble in blood It is a known fact that greater intra-abdominal pressure during laparoscopic procedures provides better and improved exposure of the operating field and allows the surgeon to perform easier operation.It is also known that the insufflation gas in the body cavity above certain value leads to a change in the body, such as disorders of homeostasis, disorders of respiratory function of the lung, and the resulting disturbance of blood gas values and the occurrence of acidosis. 1Furthermore, increased intrabadominalni pre ssure may cause the transient disturbances of liver 1,2 fun c tion, kidney 1,2,3 and a series of hemodynamic changes in organism. 1Momentary pathophysiological chan ges that occur in the body during laparoscopy with stan dard insufflation pressure are shown in Table 2.In patients with severe cardiorespiratory disease, patients with tumors, traumatized patients and patients with already impaired renal function and liver, there is a high risk in the application of standard methods with standard laparoscopy with intra-abdominal pressure of 14 mm / Hg due to the possible emergence of numerous complications, 1,4-8 ,14 Overview of basic possible complications caused by CO 2 pneumopreitoneum pressure laparoscopy in abdominal surgery can be seen in Table 3.

Increased intracranial pressure
Due to all the abovementioned, a way to make an adequate exploration of abdominal laparoscopic procedure and to avoid the possible complications and adverse effects of pneumoperitoneum on the whole organism and intraabdominal organs was required.It was necessary to reduce or eliminate the negative effects of insufflated gas in the stomach in order to avoid possible complications listed.Hence, the alternative techniques in laparoscopy, which can reduce the negative effects of CO2 pneumoperitoneum, reduce risks for patients and istoveremeno raise the abdominal wall and allow the surgeon to perform smooth operation, were created.
Alternative techniques can be divided into three groups: • Laparoscopy using pneumoperitoneum intraabdominal low pressure (up to 8 mm / Hg); 1,3,7,8 • Laparoscopy using retractors of abdominal wall and limited pneumoperitoneum (up to 5 mm / Hg); 9 • Laparoscopy without the use of gas (gasless laparoscopy; raising the abdominal wall retractor only). 10,11ese techniques represent a good alternative for the app lication of laparoscopy in cases where there are high risks for the use of a standard pneumoperitoneum with the values of pressure in the abdomen from 12-14 mm / Hg.[11][12][13][14][15] Laparoscopy with low pressure intrabadominalnim In cases when it comes to difficult patients with impaired cardiorespiratory reserve, laparoscopic surgery can be done at the IAP of 8 mm / Hg.Since laparoscopic cholecystectomy is considered to be the gold standard in chronic calculus cholecystitis, this procedure can be done by applying low pressure pneumoperitoneum, and in patients with heart comorbidity.Of course, it is necessary to raise the insufflation pressure in the abdomen to 15 mm / Hg at first, in the process of establishing pneumoperitoneum, and setting the primary and secondary trocar,.][12][13][14]15 There are many benefits of insufflation pressure not exceeding 8 mm / Hg.At this pressure , there are no disorders in the body caused by pneumoperitoneum of 14 mm / Hg.Changes in liver function, kidney function and respiratory changes are almost non-existent in patients done by low pressure, especially when it comes to shortterm laparoscopic surgical procedures and when it comes to ASA I or ASA II patients. 7,8,15What may represent less difficulty in dealing with this low pressure is the fact that the free space of the abdominal cavity is decreased, which can make it more difficult for the surgeon during the laparoscopic surgery.If it is a case of less experienced surgeon or complex laparoscopic surgery, sometimes it is not possible to perform the surgery at this pressure in abdomen.In that case, it is advisible to apply some of the alternative techniques, gasless laparoscopy or open, conventional method.
It has also been established that laparoscopy with low pressure in the abdomen causes less postoperative pain, and less frequent pain in the right shoulder and avoids the side effects of increased insufflation pressure on the liver.Also, when it comes to an experienced surgeon, the safety of operation with low insufflation pressure is no less than when working with standard pneumoperitoneum.There is no evidence of differences in the number of complications, mortality and frequency conversion between working with low and high insufflation pressure.It has also been proved that the method of laparoscopic cholecystectomy in low insufflation pressure (8 mm / Hg) does not lead to reduced blood flow through the liver and other abdominal organs which occurs in standard pneumoperitoneum of 14 mm / Hg. 7,[8][9][10][11][12][13]17 Distribution of mean values of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) during laparoscopic cholecystectomy in insufflation pressure of 8 and 14 mm / Hg is shown in Chart 1. Lowsufflation pressure in the abdomen during laparoscopy is beneficial for the patients with laparoscopic procedures and its routine use in elderly patients or patients with severe cardiorespiratory diseases should be common practice.Routine usage of low insufflation pressure in patients with severe hemodynamic and cardiorespiratory disorders are recommended by many surgeons.2,3,8,13-15-17 Regardless the numerous studies that favor laparoscopy with low insufflation pressure, most surgeons do not perform it routinely, but selectively, according to the needs and condition of the patient, which is probably the most appropriate.Cooperation between surgeons and anesthesiologists in terms of determining the modes and values of intra-abdominal pressure during laparoscopy is very important.

Laparoscopy using retractors and limited pneumoperitoneum
Simultaneous use of retractors (erector) of the abdominal wall and limited pneumoperitoneum to IAP values of 3-4 mm / Hg is a very favorable technique that does not have some influence on the organism as a standard pneumoperitoneum as the limited insufflation gas allows the surgeon to perform the operation more easily.The first techniques of the usage of retractors of abdominal wall implied partial insufflation of the abdominal cavity in order to achieve better overview. 18The list and history of these instruments are presented in Table 4. T-shape erector of abdominal wall is designed to be inserted into the abdomen through a trocar with a slight lifting of the anterior abdominal wall, after which the abdomen inflates gas of up to 8 mm / Hg. 19 U-shaped retractor is designed to require limited insufflation gas during its setting (up to 4 mm / Hg).After installation, there is no need for gas because it is possible to achieve exposure of the operative field with the reactor only. 9,10,18,19Elevation of leagues falciform is performed with specially made polyethylene bent trocar.Various modifications of the retractors were made with the aim of raising the abdominal wall by lifting leagues falciform.This method is applied along with the pneumoperitoneum low pressure. 9,18,19cheme of different types of retractors abdominal wall that require limited and insufflation gas can be seen in Figure 1.

Gasless laparoscopy
Elevation of the abdominal wall without using any gas and with the help of special retractors is defined as gasless laparoscopy. 18,20,21This method was first applied by Nagai in 1991 during laparoscopic holicistectomy. 20ypes of retractors of the abdominal wall that does not require pneumoperitoneum are displayed in Table 5.In the method promoted by Nagai, it is a common practice to use Kirscner's wires that are placed subcutaneously in the appropriate places of anterior abdominal wall.
The wires are attached to a special L retractor which is attached to the operating table. 20Modification of this method of raising the anterior abdominal wall was done by Hashimoto in 1993 who used two 30 cm-long Kirscner's wires attached again to the special retractor that was attached to the operating table. 21Chin and Moll were the first to announce and introduce the usage of the technique of flat-raising abdominal wall. 22Original system is standardized, produced and is available under the name LAPAROLIFT.Conventional retractors of different manufacturers are also in use during gasless laparoscopy and they require special minor incision upon the setting up the.They may occur in different shapes.Schematic outline of gasless laparoscopy is displayed in Figure 2. The technique of setting LAPAROLIFT system in gasless laparoscopy • Reinforce the retractor to the side of the operating table before cleaning the operative field.• Standard preoperatively cleaning of the abdomen, and before covering the same, it is necessary to enfold the retractor in transparent plastic bag.• The standard approach for almost all intra-abdominal laparoscopic procedures is periumbilical area.• Make a small incision in the abdomen to set the retractor to lift the abdominal wall.• They should be different forms of reactors available retractors: array, ring, etc. • After entering the abdomen, open the retractor.• Anchor the retractor set in the belly to the LAPAROLIFT.
Activate the Laparolift to the values that are equivalent to an intraabdominal pressure of 15 mm / Hg.

• Set a laparoscope into the abdomen through an periumbical incision
Instruments are set through a trocar or small incision (2 cm).When it comes to this technique, laparoscopic instruments or all the longer instruments for open surgery can be used.Cleaning the operative field is possible with traditional instruments for suction and irrigation without the possibility of loss of pressure at the CO2 pneumoperitoneum.
Potential advantages and disadvantages og gasless laparoscopy in comparision to standard laparoscopy using CO2 with IAP of 14 mm / Hg are shown in Table 6.Gasless laparoscopy was created because of the need to prevent the negative effects of increased intra-abdominal pressure on the body during laparoscopy, primarily in patients with comorbidity (ASA III and ASA IV).Gasless laparoscopy does not lead to significant hemodynamic changes in the body, 23,24, there are no reports on reduced kidney nor liver function, 25,26 the body's response to stress is lower, as well as post-operative pain and sickness. 23,26,27espite these advantages, the main reason for many surgeons to put this technique in 1 st place is work and adequate visualization of intra-abdominal area which often result in higher number of conversions in these methods. [26][27]

Conclusion
Direct and indirect effects of CO2 pneumoperitoneum on the body during laparoscopy in abdominal surgery in high risk patients may cause certain complications or lead to the inability of laparoscopic techniques.In these cases, it is possible to use a laparoscopic technique with low IAP, which is slightly more technically demanding for the surgeon, but could be the method of choice for the patient.Laparoscopic techniques that apply lifters (ecarters) of an abdominal wall or as they are also called gasless techniques, have not become a coompn practic nor have they implemented in our country and in the world.The reason lies in the fact that the gasless techniques are often longer in performance, complicated for the surgeon, expensive and require additional equipment.Also, the operative field is not as comfortable as shown in the case of CO2 pneumoperitoneum.Many surgeons find low IAP to be the most favorable technique of laparoscopy in patients with comorbidity and ASA III-V ASA status.Low insufflation pressure in the abdomen (up to 8 mm / Hg) is beneficial for patients with laparoscopic procedures and its routine usage in elderly patients or patients with severe cardiorespiratory diseases, should be a common practice.

TYPE
STANDARD disorders caused by PNP (12-15 mm / Hg) Cardiovascular and hemodynamic disorders • Decreased venous flow to the heart • Increased consumption of O2 level • infarction • The reduction of cardiac output • The increase in systemic vascular resistance • The increase in vascular resistance in the lung Respiratory disorders • The increase in Pa CO2 • Decreased arterial pH (acidosis) • Decreased functional residual capacity • Increase anatomic dead space • PaO2 unchanged Hypoperfusion abdominal organs • Hepatoporalni effects o the transient hypoperfusion hepatocytes o the increase in aminotransferases o the reduced flow through the portal vein and a, hepatik • Splanchnic effects o Reduced airflow through the stomach and other organs • Renal effects o reduction of renal blood flow o the lower glomerular filtration rate • Increased venous thrombosis in the lower extremities and abdomen

7 Chart 1 .
Distribution of mean values of ALT and AST during laparoscopic cholecystectomy in insufflation pressure of 8 and 14 mm / Hg(Hasukić, 2005)

Figure 1 .
Figure 1.Different types of retractors of abdominal wall which demand a limited gas insufflation

Figure 2 .
Figure 2. Scheme gasless laparoscopy with the help of LAPAROLIFT

Table 2 .
1he pathophysiological effects of increased intraabdominal pressure on organism1

Table 3 .
Transient disturbances caused by increased IAP during laparoscopy in abdominal surgery.

Table 4 .
History of different types of retractors abdominal wall that require limited and insufflation gas

Table 5 .
Types of retractors the anterior abdominal wall that does not require pneumoperitoneum

Table 6 .
Advantages and Disadvantages of gasless laparoscopy compared to standard laparoscopy with CO2 using the IAP of 14 mm / Hg