43. Pros and Cons of Alternate Gases and Abdominal Wall Lifting Methods
Robert Talac, M.D., Ph.D.
Heidi Nelson, M.D., F.A.C.S.
Modern surgery has become complex and technically sophisticated. This is particularly true for minimally invasive surgery, in which laparoscopy replaces laparotomy as the method of exposure for abdominal surgery. Adequate expo- sure of the region of interest remains one of the fundamental principles of surgery, and at the same time it represents one of the limiting factors in the devel- opment of laparoscopy. Currently available data suggest that adequate exposure can be achieved using a variety of approaches. As with all surgical procedures, understanding the advantages and disadvantages of different approaches that have been used for this purpose is essential for performing laparoscopy in a safe manner, allowing for better patient care. In this chapter, the current literature is reviewed and several different techniques for exposure of the operative field in laparoscopic surgery are discussed, including pneumoperitoneum and abdomi- nal wall lifting.
A. Pneumoperitoneum
Laparoscopy with pneumoperitoneum represents the oldest and still most common approach for establishing a working space in the peritoneal cavity.
1. Advantages
a. The pneumoperitoneum results in a symmetrical dome- shaped elevation of the abdominal wall that usually provides excellent exposure of the abdominal cavity and adequate working space. In regard to intraabdominal exposure, no mechanical retraction system can compete with pneumoperi- toneum. Pneumoperitoneum provides simultaneous exposure of all quadrants of the abdominal cavity, which allows the perfor- mance of more complex laparoscopic procedures. Pneumoperi- toneum, therefore, is the “gold standard” against which other methods should be compared.
b. Establishment of pneumoperitoneum with CO2is inexpensive and usually safe. Although complications can occur when the pneumoperitoneum is established, in most cases it is a safe method.
2. Disadvantages
a. Gas insufflation-related complications. Complications, albeit exceedingly rare, are most likely to occur when the “blind” Veress needle insertion method is used for insufflation. The most feared complication is a gas embolus. If an “open” cut-down method is used to place the first port, through which the pneumoperitoneum is next established, then most pneumoperitoneum establishment- related complications, including gas embolism, can be avoided.
However, rarely, the bowel can be injured with either the Veress or open cut-down method.
b. Adverse physiologic effects. These effects limit the safety of longer, more complex laparoscopic procedures or procedures performed in high-risk patients (Tables 43.1, 43.2).
c. Effects of pneumoperitoneum on tumor cell implantation fol- lowing laparoscopic surgery for cancer. A number of experi- mental studies using animal models have demonstrated that laparoscopy with CO2insufflation is associated with a significant increase in the incidence of port site metastasis as well as dis- semination and implantation of intraabdominal tumors. However, these findings do not correlate with results of human studies.
Numerous investigators have shown that the rate of port site recurrences ranges from 0% to 2%, which is similar to incidence of wound recurrences documented after open procedures. So far, there is a paucity of information on the etiology of port site recur- rences in humans. The fact that wound implants are absent in some laparoscopic series suggests that such recurrences might be related to technical details in performance of the procedure rather than to the pneumoperitoneum.
Table 43.1. Effects of increased intraabdominal pressure on cardiac functions.
—≠Atrial filling pressure
—≠Pressure in inferior vena cava
—ØVenous return Alteration of cardiac output
— Elevations of diaphragm Stroke volume, ejection fraction
—≠Intrathoracic pressure
—ØLeft ventricular filling
Table 43.2. Effects of increased intraabdominal pressure on renal functions.a
—ØCardiac output
—ØRenal venous pressure —ØEffective renal plasma flow
— Compression of the renal parenchyma —ØGlomerular filtration rate
— Release of vasoconstriction — Oliguria Hormones (angiotensin II and
vasopressin)
aNote: Despite these effects, no long-term renal sequelae, even in patients with preexist- ing renal disease, have been reported after pneumoperitoneum.
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d. Technical disadvantages. The constraints of working in a sealed environment restrict the spectrum of instruments available for laparoscopic surgery.
e. Safety concerns. Additional concerns related to the use of various gases and their safety in the presence of electrocautery or laser coagulation and the risk of exposure to operating room personnel must be considered.
In an effort to minimize the disadvantages of pneumoperitoneum, several insufflating agents have been explored. These include carbon dioxide, nitrous oxide, helium, and argon. Specific issues related to each agent are summarized in Table 43.3.
B. Abdominal Wall Lifting Techniques
Because of adverse physiologic effects and the technical disadvantages of the pneumoperitoneum, alternative methods of intraabdominal exposure have been designed and tested. The fundamental principle of a variety of abdominal wall lifting devices is the application of vertical upward forces to lift the ante- rior abdominal wall to create a space similar to that produced by pneumoperi- toneum. Currently, two groups of retraction systems exist. These include (1) intraabdominal retraction systems and (2) subcutaneous lifting of the abdomi- nal wall. Table 44.4 lists and describes the available lifting devices and methods.
1. Advantages
a. No alteration of cardiac, pulmonary, or renal functions.
Recent studies comparing pneumoperitoneum and abdominal wall lifting in terms of hemodynamic responses demonstrated no alteration of cardiac output, stroke volume, ejection fraction, effective renal plasma flow, and glomerular filtration rate in patients operated on using the abdominal wall lifting device.
These parameters do not change even in the reverse Trendelen- burg position. However, no difference in stress response has been noted when patients undergoing pneumoperitoneum have been compared to those in whom an abdominal wall lifting method has been used.
b. Combination of laparoscopic and conventional instruments.
In the absence of a pneumoperitoneum, there is the possibility of introducing conventional instruments into the abdominal cavity.
The utility of conventional instruments in this setting, however, is limited due to instrument length, restrictions in opening of the jaws that result when passing such instruments through a small wound, and the narrow range of movement that the wound pro- vides. These problems have led some to design conventional instruments for gasless laparoscopy.
c. Regain tactile sensitivity. The loss of tactile sensitivity of the surgeon using the minimally invasive approach to target area is a well-recognized disadvantage. The concept of laparoscopy 420 R Talac and H Nelson
Table 43.3.Insufflating agents available for laparoscopy with pneumoperitoneum. Physical GascharacteristicsProsConsComments Carbon dioxide— Odorless— Low risk of gas embolism— HypercarbiaMost common agent used (CO2)— Colorless— Safe with electrocautery and— Respiratory acidosisin the US — Stable gaslaser coagulation— Pain — Readily available— Adverse effects on — Inexpensiveautonomic nerve — Highly solublesystem Nitrous oxide— Odorless— Minimal alteration of acid-— CombustibleSuitable for procedures (N2O)— Colorlessbase balance— Safety concerns withperformed under local — Soluble in blood and— Minimal discomfort and painexposure of personnelanesthesia body fluids Helium (He)— Odorless— Minimal alteration of acid-— Postoperative — Colorlessbase balancesubcutaneous — Inert gas— Safe with electrocautery andemphysema — Poor water solubilitylaser coagulation— Potential risk of — Poor solubilityvenous gas embolism Argon (Ar)— Odorless— Minimal alteration of acid-— Cardiac depressionLimited data available to — Colorlessbase balanceeffect (in animaljustify feasibility of — Inert gas— Safe with electrocautery andmodel)argon pneumoperitoneum — Poor blood solubilitylaser coagulation — Poor solubility
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Table 43.4.Abdominal wall lifting systems. SystemTypeLifting methodPneumoperitoneum requirements Abdominal Cavity Expander SystemIntraabdominal retractionPointPermanent low-pressure pneumoperitoneum SlingIntraabdominal retractionPointPermanent low-pressure pneumoperitoneum T-shaped endoscopic retractorIntraabdominal retractionPointPermanent low-pressure pneumoperitoneum Spreading trocarsIntraabdominal retractionPointInitial pneumoperitoneum Peritoneal Cavity AugmentationIntraabdominal retractionLinearPermanent low-pressure pneumoperitoneum Winch retractorIntraabdominal retractionLinearInitial pneumoperitoneum Coathanger-shaped retractorIntraabdominal retractionLinearInitial pneumoperitoneum U-shaped retractorIntraabdominal retractionLinearInitial pneumoperitoneum Suspensor 3-XIntraabdominal retractionPlanarInitial pneumoperitoneum Pelvi-SnakeIntraabdominal retractionPlanarInitial pneumoperitoneum Modular retraction systemIntraabdominal retractionPlanar0 LaparoliftIntraabdominal retractionPlanar0 Tent-shaped wiringSubcutaneous retractionLinear0 Subcutaneous wiringSubcutaneous retractionLinear0 Laparo TenserSubcutaneous retractionPlanar0
without pneumoperitoneum allows the surgeon to combine the advantages of laparoscopic surgery (i.e., magnified visualization of target area) with well-known open surgical techniques. The ability to combine fully laparoscopic dissection of fine tissue structures with digital palpation and dissection may facilitate the performance of minimally invasive procedures.
2. Disadvantages
a. Suboptimal exposure of abdominal cavity represents a major disadvantage of abdominal wall lifting devices. The distension that is provided by pneumoperitoneum is dome shaped, whereas the exposure provided by the intraabdominal retractors resembles a flat-topped pyramid and is limited to a specific quadrant of the abdomen. Quadrant-specific exposure may be adequate for certain procedures such as cholecystectomy or appendectomy.
However, suboptimal exposure in more complex procedures requiring multiquadrant exposure such as laparoscopy-assisted colectomy may lead to serious complications and/or violating of sound surgical principles. It has been suggested that the “tenting”
problem may be corrected by subcutaneous lifting methods.
b. Specific concerns. Several abdominal wall-lifting systems require an additional permanent low-pressure pneumoperitoneum due to inadequate exposure of the target area. The advantages of this approach are minimal. Other systems require pneumoperi- toneum only for the safe installation of the lifting device. This approach bears the same risk of gas insufflation-related compli- cations such as reported for pneumoperitoneum. Because of tent- shaped suspension and suboptimal intraabdominal exposure, applications of this approach have been limited to procedures in the pelvic region. In addition, there is a possibility of ischemic injury to abdominal wall muscles with intraabdominal lifting devices. Some of these problems can be overcome using subcu- taneous retraction systems. These do not require an initial pneu- moperitoneum; however, to achieve adequate exposure CO2
insufflation must be added in some situations. Moreover, setting up a system of subcutaneous wiring is more complicated.
c. Limited application in certain patients. The initial experiences with abdominal wall lifting devices have shown that exposure is very poor in individuals with a muscular abdominal wall or obese patients.
d. The abdominal lifting device can present an obstacle for a surgeon performing minimal-access surgery.
The concept of gasless laparoscopy is certainly valid. The technique is in its infancy, and further developments are required such that the exposure provided is comparable to that provided by pneumoperitoneum. It is conceivable that gasless laparoscopy will have value in high-risk patients, particularly those with cardiopulmonary disease.
C. Selected References
Corwin CL. Pneumoperitoneum. In: Scott-Conner CEH (ed) The SAGES Manual: Fun- damentals of Laparoscopy and GI Endoscopy. New York: Springer, 1998:37–42.
Gutt CN, Daume J, Schaeff B, Paolucci V. Systems and instruments for laparoscopic surgery without pneumoperitoneum. Surg Endosc 1997;11:868–874.
Kurauchi N, Yonekawa M, Kurokawa Y, et al. Comparison between CO2insufflation and abdominal wall lift in laparoscopic cholecytectomy. A prospective multiinstitutional study in Japan. Surg Endosc 1999;13:705–709.
Neuhaus SJ, Ellis T, Rofe AM, Pike GK, Jamieson GG, Watson DI. Tumor implantation following laparoscopy using different insufflation gases. Surg Endosc 1998;12:
1300–1302.
Ninomiya K, Kitano S, Yoshida T, Bandoh T, Baatar D, Matsumoto T. Comparison of pneu- moperitoneum and abdominal wall lifting as to hemodynamics and surgical stress response during laparoscopic cholecystectomy. Surg Endosc 1998;12:124–128.
Paolucci V, Schaeff B, Gutt CN, Litynski GS. Exposure of the operative field in laparo- scopic surgery. Surg Endosc 1997;11:856–863.
Wolf JS, Stoller ML. Physiology of laparoscopy: basic principles, complications and other considerations. J Urol 1994;152:294–302.
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