Is laparoscopy really minimally invasive

Views:
 
Category: Education
     
 

Presentation Description

Why minimal invasiveness of laparoscopy is not always guaranteed ?

Comments

Presentation Transcript

Is laparoscopy really minimally invasive ??:

Is laparoscopy really minimally invasive ?? BY Hosam Mohamad Hamza, MSc Assistant Lecturer of General Surgery And Laparo-endoscopy Minia Faculty of Medicine EGYPT Jan 2014

PowerPoint Presentation:

Minimally Invasive Surgery (MIS) Definition: A philosophical approach to surgery in which the trauma of surgical access is minimized without compromising the quality of the surgical procedure. Historical background: Although the term is relatively recent, the history of MIS is not new. The use of tube and speculum in medicine dates from the earliest days of civilization in ancient Greece. LAP that is considered the newest and most popular variety is, in fact, the oldest (primitive laparoscopy, placing a cystoscope within an inflated abdomen, was first performed by Kelling in 1901).

PowerPoint Presentation:

Historical background, contd : The explosion of video-assisted surgery in the past 30 years changed our understanding of surgical anatomy and reshaped surgical practice. Lap-guided gall stone clearance was 1st performed in animal model by Frimberger and associates in Germany in 1971. In 1987, Mouret (Lyon, France) was the 1 st surgeon to perform cholecystectomy in human using standard laparoscopic equipment, then, great advances follow in lap. techniques in various specilalities . The motivation to develop surgical robots was to overcome the limitations related to the technical and mechanical nature of lap. equipment as: - Loss of tactile feedback. - Loss natural hand-eye coordination. - Fulcrum effect. - Amplification of physiologic tremors of the surgeon.

PowerPoint Presentation:

Historical background, contd : RoboDoc (a robotic system designed to drill the femur shaft in hip replacement) was the 1 st computer-assisted surgical robot approved by the FDA in the late 1980's. Advances then continue till introduction of the Automated Endoscopic System for Optimal Positioning (AESOP), a robotic arm controlled by the surgeon's voice commands and Da Vinci and Zeus surgical systems. IN THE FUTURE , equipped nanorobots introduced through BVs and guided by a human surgeon may be capable of performing precise intracellular surgeries beyond the capabilities of the human / robotic hand.

PowerPoint Presentation:

LAPAROSCOPY Definitions: LAP is inspection of the peritoneal cavity with a telescope introduced through the abd wall after creation of pneumoperitoneum . Lap. surgery is the execution of an established surgical procedure by remote manipulations within the closed abd cavity using LAP . Advantages (rationale for minimally invasive surgery) : ☞ Minimal invasion Minimization of body invasion & parietal trauma (avoiding large access wounds). Significant ↓ of postop. pain. Significant ↓ of periop . morbidity: ↓ cardiopulmonary complications. ↓ postop. ileus. ↓ postop. adhesions. ↓ wound complications (e.g. infection, dehiscence, …. ). ↓ cosmetic insult.

PowerPoint Presentation:

4. ↑ Speed of recovery. 5. Minimization of the stress response to surgery (decreased levels of catecholamines , cortisol, glucose and other acute phase reactants compared with laparotomy). 6. Minimization of surgery-induced immunosuppression (preserved cell mediated immunity compared with laparotomy) that may have important implications esp in cancer surgery. ☞ Visual enhancement: by the magnifying effect of the telescope. ☞ ↓ incidence of infection: The greatly ↓ contact with patient's blood and body fluids ↓ transmission of viral diseases for both patient and surgeon.

PowerPoint Presentation:

DIFFICULTIES (disadvantages): minimized by appropriate training and experience ☞ Equipment-related: Necessity to purchase & maintain expensive high technology equipment. ☞ Procedure-related : Necessity for insufflation (effects of pneumoperitoneum ). Necessity to access space via needle & trocars (risk of visceral injury ). Diathermy injuries . Haemostasis can be difficult to achieve. Intact organ retrieval , particularly if tumourous , may be seriously limited . ☞ Surgeon-related : Requires more technical expertise and long time, at least initially. Loss of touch sensation & tactile feedback. Loss of 3-D visualization ( images of current camera systems are 2-D). Loss of eye/hand co-ordination. Limited degrees of motion . 6. Fulcrum effect . Amplification of the surgeon's physiologic tremors through the length of rigid instruments.

PowerPoint Presentation:

INADVERTENT PNEUMO PRE PERITONEUM PHYSIOLOGICAL CHANGES WITH PNEUMOPERITONEUM PHYSIOLOGICAL CHANGES WITH PATIENT POSITIONING GASLESS LAPAROSCOPY

PowerPoint Presentation:

Inadvertent Pneumo-preperitoneum 2% of cases. Diagnosis: 1. Drop or aspiration test. 2. palpation of crepitus under the skin. 3. typical spider-web appearance after inserting the 1 st cannula (further stripping of peritoneum by the telescope tip is to be avoided) Management: if detected early (before cannula insertion) : * allow gas to escape. * then re-introduce needle through the same or another site. g If detected after cannula insertion: * withdraw cannula & telescope. * allow gas to escape. * re-introduce needle or use “open technique”.

PowerPoint Presentation:

PHYSIOLOGICAL CHANGES WITH PNEUMOPERITONEUM The singular feature of laparoscopy is the need to lift the abd wall from abd organs. 2 methods: IDEAL GAS FOR INSUFFLATION Colourless . Non expensive. Non explosive (doesn’t support combustion). Non toxic. Limited systemic absorption across peritoneum. Limited systemic effects if absorbed. Rapid excretion if absorbed. High solubility in blood. Gasless laparoscopy . Pneumoperitoneum and

PowerPoint Presentation:

Throughout the early 20 th century, pneumoperitoneum was achieved by inflating the abd cavity with air using sphygmomanometer bulb. CO 2 and N 2 O were then used. CO 2 N 2 O More soluble. Less expensive. Doesn’t support combustion. Readily available . Highly soluble. Better analgesia. ↓ intraoperative end-tidal CO 2. Insignificant acid/base imbalance. Advantages Acidosis: Cardio-depression Pulmonary HTN Systemic VD v Hypercarbia : Sympathetic ++ Tachycardia , Arrhythmias , HTN H h Stored CO 2 may take hours to be eliminated. Possibility of combustion . Lap. cancer surgery ( CAUTION ). Safety in pregnancy has yet to be elucidated. Disadvant .

PowerPoint Presentation:

CO 2 pneumoperitoneum Physiologic effects of CO 2 pneumoperitoneum can be divided into : (a ) local effects. ( b) systemic effects .

PowerPoint Presentation:

A. LOCAL (abdominal) EFFECTS OF PNEUMOPERITONEUM: Peritoneal distention: and postoperative pain. Elevated diaphragm. Vagal Stimulation: A rapid stretch of peritoneum often causes a vagovagal response with bradycardia ( commonest cardiac dysrhythmias with laparoscopy ) and, occasionally, hypotension. Appropriate management is: _ desufflation of the abdomen _ vagolytic agents (e.g., atropine) _ adequate volume replacement. 4. Adhesions: Peritoneum is a 37 °C potential space covered by a wet film of fluid. The currently used CO 2 is instilled at 21°C and extremely dry . A bsence of water in a gas going into a wetted cavity causes t issue desiccation and damage that precede adhesion formation .

PowerPoint Presentation:

B. SYSTEMIC EFFECTS OF PNEUMOPERITONEUM: 1. Hypothermia: Absence of water in a gas going into a wetted cavity causes evaporative hypothermia 2. Respiratory effects: a . Respiratory acidosis and hypercarbia : Insufflation → CO 2 is rapidly absorbed → hydration to carbonic acid in RBCs (buffering capacity of Hb ). Respiratory acidosis is prevented by body buffers . Once the body buffers are saturated, acidosis rapidly develops. Mild respiratory acidosis is probably an insignificant problem. More severe respiratory acidosis = cardiac arrhythmias Hypercarbia = tachycardia & ↑ systemic vascular resistance=↑BP& ↑myocardial O 2 demand . In patients with normal respiratory function; anesthesiologist should ↑ the ventilatory rate on the ventilator (within limits). In some situations, it is advisable to reduce the IAP (or even evacuate the pneumoperitoneum ) to allow time for the anesthesiologist to adjust for hypercarbia .

PowerPoint Presentation:

b. increased intrathoracic pressure: The direct effect of pneumoperitoneum leads to: ↑ intrathoracic pressure . ↑ pressure across the chest wall. ↑ likelihood of pulmonary barotrauma . c. pneumothorax: ( esp in lap. surgery at the GO junction ) Mechanisms: 1. gas tracking : _ along the tissue planes & potential channels _along surgically traumatized pleura _along undetected diaphragmatic hernia 2. Barotrauma (rupture of an emphysematous bleb). Detection : Unexplained Occurrence Of One Or More of the following should alert us to the possibility of pneumothorax: 1* sudden ↓ oxygen satura­tion 2*↓ motion of hemidiaphragm 3* ↓ air entry on auscultation 4* ↑ airway pressure

PowerPoint Presentation:

c. pneumothorax, contd : Management: 1 . DON’T RUSH for an ICT. 2. PEEP (if NO pulmonary barotrauma). 3. Stop gas. 4. Exsufflate . 5. Tube drainage (if spontaneous resolution does not occur for 1 hour of exsufflation ). d. Endobronchial intubation: dt upward tracheal displacement during high P peritoneal insufflation. If occurs → bronchospasm, hypoxia and atelectasis . Position of the ETT should always be checked intra-operatively.

PowerPoint Presentation:

e . Aspiration of gastric contents : due to: 1* increased intra-abdominal pressure 2* change in posture 3* manipulation of the stomach Risk is reduced by appropriate NG and ET tube placement . f . Gas embolism: R are but SERIOUS (potentially lethal ). Causes my include: 1* inadvertent intravascular gas in­j. through a misplaced Veress needle 2* forcing of gas into a vein splinted open 3* extensive argon beam use in LH (argon gas embolism)

PowerPoint Presentation:

Clinical effects:   Cerebral gas embolism Pulmonary gas embolism - May occur as a result of gas entering the systemic circulation via a patent cardiac foramen or through the pulmonary capillary system. - C an result in neurological dysfunction (d elayed recovery, coma, fits, paresis) - Slow infusion of CO 2 is readily absorbed across the capillary - alveolar membrane. - High rates → bronchospasm & pulmonary oedema . - Large infusion rates ≥ 3 ml/kg → airlock at rt ventricle→ cardiovascular collapse . 1. Physiological effects depend on rate & volume of gas . 2. Effect tends to be less dramatic with CO 2 . 3. May occur as a delayed phenomenon (if gas is trapped in the portal circulation).

PowerPoint Presentation:

DIAGNOSIS of gas embolism during laparoscopy: Suspect if hypotension develops during insufflation. Oesophageal stethoscope= characteristic "Mill wheel" murmur. Transoesophageal Echosonography : can detect even subclinical embol­i Treatment: G A S G et rid of emboli: _ place the patient in left lat. decubitus with the head down . _ rapidly placed central venous catheter → foamy blood. _ external cardiac massage . A sk for _ 100% O 2 _ hyperventilation _ I.V. fluids 3. S top gas: _ turn-off gas flow. _ desufflate the abdomen.

PowerPoint Presentation:

3. Cardiovascular effects : " more marked during the initial 30 min of insufflation" a. ↓ COP: due to ↓VR secondary to: excessive pressure on IVC . reverse Trendelenburg's (lap . upper abdominal op .) loss of LL muscle tone . this decrease is not seen if: patient is normovolaemic . IAP is kept under 20 mmHg. b. ↑ CVP: ↑ IAP is transmitted directly across the paralyzed diaphragm to thoracic cavity→↑ CVP c. ↑ mean ABP: due to ↑ systemic vascular resistance by: mechanical compression of aorta & splanchnic vessels. neurohumoral factors (e.g. vasopressin, catecholamines ) Reverse Trendelenburg position can compensate for ↑ ABP ( gravitational effect ).

PowerPoint Presentation:

d.↑ risk of thromboembolic events : venous engorgement & ↓VR . Many advanced lap. procedures in which DVT prophylaxis was not given demonstrate the frequency of pulmonary embolus. This usually is an avoidable complication with the use of: * sequential compression stockings. * LMWH. In short-duration lap. procedures (e.g. appendectomy, hernial repair or cholecystectomy), the risk of DVT may not be sufficient to warrant extensive DVT prophylaxis.

PowerPoint Presentation:

4. Oliguria: Intraoperative oliguria is common with laparoscopy due to: ↑ IAP → direct pressure on kidney & its BVs → ↓RBF→ ↓ GFR. ↑ circulating ADH levels that also are found during pneumoperiton . ↓ RBF →↑ plasma renin→↑ Na retention . NB Effects of pneumoperitoneum on RBF are immediately reversible. Hormonal changes can ↓UOP for up to 1 hr after procedure has ended. During LAP , UOP is not a reflection of intravascular volume status . SO…….. r egarding IV fluid administration in uncomplicated procedures: 1. IV fluid administration should not be linked to UOP. 2. Compared to open surgery, more judicious I.V. fluid use is a MUST because insensible fluid losses through the open abdomen are eliminated .

PowerPoint Presentation:

Haemodynamic consequences of pneumoperitoneum are well tolerated by healthy individuals for a prolonged period and by most individuals for at least a short period. Difficulties occur when a patient with compromised cardiovascular function is subjected to a long lap. procedure (alternative approaches should be considered). Alternative gases suggested for laparoscopy include the inert gases helium, neon and argon. They cause no metabolic effects, but are poorly soluble in blood (unlike CO 2 & N 2 O)→ prone to create gas emboli if they have direct access to the venous system.

PowerPoint Presentation:

PHYSIOLOGICAL CHANGES WITH PATIENT POSITIONING 1 . Cardiovascular changes : Head-up position: ↓VR, COP, mean ABP, ↑systemic and pulmonary vascular resistance Head-down position: vice versa Lateral decubitus position: direct pressure over the IVC may result in ↓↓↓VR→ ↓BP 2. Respiratory changes : Head down position: * ↑ the risk of: * gas embolism * hypoxia & atelectasis (by changes in intrathoracic blood volume & small airway collapse) * endobronchial intubation . * ↓: * FRC * total lung volume * lung compliance

PowerPoint Presentation:

Gasless Laparoscopy An abdominal lifting device is placed through a 10-12 mm trocar at the umbilicus t o avoid the disadvantages of CO 2 insufflation. Advantages of using abdominal lifting devices: 1* They create little physiologic derangement . 2* They significantly minimize the risk of gas embolization . 3* They may allow performing of MIS with standard nonlaparoscopic surgical instruments . 4* They eliminate the need of a gas-tight operating environment.

PowerPoint Presentation:

Disadvantages : Despite these inventions, technique of gasless LAP has not yet achieved wide popularity may be due to: The bulky nature of most of these devices. Greater postoperative pain than pneumoperitoneum . Exposure and working room are inferio r . Because the physiological effects of pneumoperitoneum appear to be most marked after initial abdominal insufflation and during high pressure insufflation (> 14mmHg), the use of a hybrid system of low pressure pneumoperitoneum (<5mmHg) combined with an abdominal wall retracting technique may provide the best of both worlds.

PowerPoint Presentation:

CONCLUSION

PowerPoint Presentation:

From the surgical point of view , LAP is considered minimally invasive. From the physiological point of view and body response, a number of physiological changes occur as a result of: * p neumoperitoneum * p ostural changes involved in patient positioning . Physiologically, LAP is not considered minimally invasive , particularly in: 1. Patients with very old age. 2 . Patients with very young. 3. Patients with significant pre-existing diseases. (cardiovascular , pulmonary and neurological disorders).

PowerPoint Presentation:

3. The major problems during laparoscopic surgery are related to CO 2 -induced pneumoperitoneum , t hese problems can be averted if certain precautions have been kept in mind: All cardiopulmonary-compromised patients should be assessed preoperatively by a physician or a cardiologist . Lower pressure pneumoperitoneum (10–12 mmHg) with proper patient hydration can prevent cardiac problems. Minimize operative time by the help of experienced person. Use helium or nitrous oxide gas for pneumoperitoneum , if available in cardiopulmonary-compromised patients.

PowerPoint Presentation:

References: A Guide to Laparoscopic Surgery book Wiley-Blackwell; 1 st edition (December 15, 1998 ) ISBN-10: 086542649X ISBN-13: 978-0865426498 A Guide to Laparoscopic Surgery. Ann R Coll Surg Engl. 2000 September; 82(5): 370. Secrets of safe laparoscopic surgery: Anaesthetic and surgical considerations. J Minim Access Surg. 2010 Oct-Dec; 6(4): 91–94. Shakespeare's view of the laparoscopic pneumoperitoneum . JSLS . 2011 Jul-Sep;15(3): 282-4

authorStream Live Help